Welding Symbols

Welding cannot be used as a engineering tool unless a means is provided for conveying the information from the designer to the workmen. Welding symbols provide the means of placing welding information on drawings. The scheme for symbolic representation of welds on engineering drawings used in this manual is consistent with the "third angle" method of projection. This is the method mostly used in North America.

The joint is the basis of reference for welding symbols. The reference line of the welding symbol (see below) is used to designate the type of weld to be made, its location, dimensions, extent, contour, and other supplementary information. Any welded joint shown by a symbol will always have an arrow side and an other side.

Standard Location of Elements of a Welding Symbol

The tail of the symbol is used for designating the welding and cutting processes as well as the welding specifications, procedures, or the supplementary information to be used in making the weld. If a welder knows the size and type of weld, he has only part of the information necessary for making the weld. The process, identification of filler metal that is to be used, whether or not peening or root chipping is required, and other pertinent data must be related to the welder. The notation to be placed in the tail of the symbol indicating this data is to be established by each user. If notations are not used, the tail of the symbol may be omitted.

A distinction is made between the terms ‘weld symbol’ and ‘welding symbol’. The weld symbol indicates the desired type of weld. The welding symbol is a method of representing the weld symbol on drawings. The assembled ‘welding symbol’ consists of the following eight elements, or any of these elements as necessary: reference line, arrow, basic weld symbols, dimensions and other data, supplementary symbols, finish symbols, tail, and specification, process, or other reference.

Designation of Welding Processes by Letters.

Welding Process Letter Designation

Brazing

Torch brazing TB Twin carbon-arc brazing TCAB Furnace brazing FB Induction brazing IB Resistance brazing RB Dip brazing DB Block brazing BB Flow brazing FLB

Flow Welding

FLOW

Resistance welding

Flash welding FW Upset welding UW Percussion welding PEW Induction welding IW

Arc welding

Bare metal-arc welding BMAW Stud welding SW Gas shielded stud welding GSSW Submerged arc welding SAW Gas tungsten-arc welding GTAW Gas metal-arc welding GMAW Atomic hydrogen welding AHW Shielded metal-arc welding SMAW Twin carbon-arc welding TCAW Carbon-arc welding CAW Shielded carbon-arc welding SCAW Flux cored-arc welding FCAW

Thermit welding

Nonpressure thermit welding NTW Pressure thermit welding PTW

Gas welding

Pressure gas welding PGW Oxyhydrogen welding OHW Oxyacetylene welding OAW Air-acetylene welding AAW

Forge welding

Roll welding RW Die welding DW Hammer welding HW

Cutting Process Letter Designation

Arc cutting

AC Air-carbon-arc cutting AAC Carbon-arc cutting CAC Metal-arc cutting MAC

Oxygen cutting

OC Chemical flux cutting FOC Metal powder cutting POC Arc-oxygen cutting AOC

Letter designations have not been assigned to arc spot, resistance spot, arc seam, resistance seam,
and projection welding since the weld symbols used are adequate. The following suffixes may be used
to indicate the method of applying the above processes: